Technical Field
The present disclosure relates to a sheet transport device and an image forming system that is a combination of the sheet transport device and an image forming device.
Description of Related Art
Conventionally, there exist so-called in-body paper-ejection type image forming devices. An in-body paper-ejection type image forming device is an image forming device (e.g., a copier) that includes an image reader and an image former disposed below the image reader, with a space between the image reader and the image former. In such an in-body paper-ejection type image forming device, the image former forms an image on a sheet, such as a recording sheet, and then ejects the sheet onto an ejection tray that is disposed within the space.
Such an in-body paper-ejection type image forming device is advantageous in that the ejection tray does not protrude sideways from the image forming device. Accordingly, an in-body paper-ejection type image forming device has relatively small size in the lateral direction, which enables installation of an in-body paper-ejection type image forming device at various locations.
Japanese Patent Application Publication No. 2002-128364 (referred to as Patent Literature in the following) discloses an in-body paper-ejection type image forming device having a sheet post-processing device attached within the space (in-body space) between the image reader and the image former. The sheet post-processing device performs post-processing with respect to a sheet ejected from the image reader. The post-processing is, for example, stabling. The sheet post-processing device disclosed in Patent Literature includes a processing tray on which a stack of sheets having images formed thereon is temporarily placed for post processing, and a stack tray on which a post-processed sheet stack transported from the processing tray is placed. The processing tray and the stack tray, when the image forming device is seen from a front side thereof, are arranged next to one another in the lateral direction, with the processing tray to the left and the stack tray to the right. Due to this, the in-body paper-ejection type image forming device disclosed in Patent Literature has relatively great size in the lateral direction. Due to this, despite being an in-body paper-ejection type image forming device, the in-body paper-ejection type image forming device disclosed in Patent Literature does not have reduced size in the lateral direction.